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(No Model.)

J. H. BUNNELL. MECHANICAL TELEGRAPH INSTRUMENT. No. 418,443. PatentedDec. 31, 1889;

mummu N. PETERS. FhOlWLxllwgraphcr, Washiugwn, D c.

UNITED STATES PATENT OFFICE.

JESSE H. BUNNELL, OF NEW YORK, N. Y.

MECHANICAL TELEGRAPH-HNSTRUMENT.

SPECIFICATION forming part of Letters Patent No. 418,443, dated December31, 1889.

Application filed December 13, 1883- Renewed October 8, 1889. Serial No.326,326. (No model.)

T0 at whom it may concern:

Be it known that I, JESSE H. BUNNELL, a citizen of the United States,residing at New York, in the county of New York and State of New York,have invented certain new and useful Improvements in MechanicalTelegraph-Instruments5 and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

This invention relates to that class of devices generally known asmechanical telegraph-instrumentsthat is, an instrument for students andlearners use-which combines the functions of a telegraph key andsounder, to enable the tyre to practice both sending and receiving bysound without the expense and inconvenience of a battery and thecomplete electro-magnetic equipment.

The object of my present invention is to so construct the instrumentthat in working the key the operator will have presented to his sensesof touch and hearing precisely the same conditions as he will afterwardmeet within sending and receiving on the regularly-organized standardelectrical instruments.

My invention consists in the combination and arrangement of parts,substantially as hereinafter more particularly pointed out.

In the accompanying drawings, which form part of this specification,Figure 1 is a side elevation of my proposed instrument complete. Fig. 2is a similar elevation with half the trunnion-bridge removed. Fig. 3 isa sectional detail showing my frictionless mode of connecting thelevers, and Fig. at is a perspective of another form of connecting pieceor toggle. I

In constructing the device I prefer to mount the whole on a hardwoodbase A, which rests on projections, to make the instrument resonant. Tothe base A, I fix the trunnionbridge B, of the form most commonly usedin sounders for the lever. In this I pivot the respective levers K and Sby means of the trunnion a and trunniorrscrews c. The keylever K extendsin both directions from its trunnion. At its front end it is fitted withthe ordinary rubber finger-piece d, and its back end forms a limit-stopon the screw e in the base A. Lever K also has an upward extension f,which I prefer to have immediately above its trunnion. The sounder-leverS is pivoted at a point above the trunnion of keylever K, and extendsback between the jaws 1 and 2 of a regular sounder bridge or arch T,which is firmly secured to the base A. The jaw 1 is fitted with theadjustable back stop 3, and the lever S is fitted with the adjustablefront stop at, which strikes the'arch T just as the ordinaryelectromagnetic sounder is constructed at its corresponding portion.Lever S has a downward extension g, and the exten sions f and g are soproportioned as to overlap, as shown, but with their adjacent faces inclose proximity. Between the two I insert a short pointed toggle 2',whose ends rest in depressions or recesses in the adjacent faces of thelever-extensions f and g. The levers are held in this relation by aspring m, which also acts to throw up the rear end of the lever S and tolift the key K into its upper position. The spring on is made to adjustthe tension or stiffness of the key by being looped over a notched pinn, projecting from the lever S. I thus obtain an instrument whichexactly imitates every one of the functions of the regular standardtelegraphic key and sounder, and so perfect is this imitation that whenthe spring is properly adjusted the most experienced operator finds nodifference whatever, so far as relates to the touch in sending or thesound in receiving.

The apparatus is cheap to construct, substantial, and durable, andisquite portable for pocket use, as it occupies but little more spacethan the standard telegraphic key.

The method of connecting the levers K and S is admirably suited to theobject, and forms an important feature of my invention. Instead,however, of using a double-pointed toggle I can adopt the toggle shownin Fig. 4, consisting of a flat piece of steel 1', having a knife-edgeat each end, and this may be of IOO pendentlypivotedin a singlebridgeand having overlapping extensions held in operative connection by asingle spring attached to both levers, substantially as described.

2. In a mechanical telegraph-inst'rument, a-

key-lever and a sounding-lever, both independently pivoted in a singlebridge and having overlapping extensions operatively connected by aninterposed toggle, in combination with a spring attached to both leversand adapted to force both said extensions against the toggle,substantially as described.

3. In a mechanical telegraph-instrument, the combination of the pivotedlever K, having fingerpiece d and upward extension f, the pivoted leverS, having the downward extension g, the toggle z, interposed betweensaid extensions, a spring m, connected to said levers, and suitablesounder stops or jaws embracing the extremity of the lever S,substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

JESSE H. BUNNELL.

Witnesses:

\VM. I -I. BULL, THos. P. CROWNE.

